The view is made up of 12 (6x2) very large plates to be tiled pasted.
In this site it is split into 72 sections: 12 numbers from left
to right (1-12) for the width and 6 letters (A-F) for
the height. You may wish to compare Vasi's view with his 1781 Map or with a
view from S. Pietro in Montorio (very close to the point from which this
view was taken) of the end of the XIXth century.